NATO fighter jets were scrambled and air defense systems placed on high alert in Poland overnight as Russia launched one of its largest drone and missile barrages of the war against Ukraine, Poland’s Armed Forces Operational Command said in a series of posts on X.

“Fighter jets have been scrambled and ground-based air defense systems as well as radar reconnaissance systems have reached a state of readiness,” the command announced, describing the actions as preventive measures intended to secure Polish airspace, particularly areas close to Ukraine.

The alert remained in effect for just under four hours, after which Polish forces “returned to standard operational activities.” No violations of Polish airspace were detected, officials said.

Poland noted that Spanish and Czech fighter jets participated in the response, alongside German and Dutch air defense systems, reflecting a coordinated NATO reaction to the escalating strikes.

According to Ukraine’s air force, Russia unleashed 653 drones and 51 missiles—including 17 ballistic missiles—overnight. Ukrainian forces said they intercepted or suppressed 585 drones and 30 missiles. Drone and missile impacts were reported in 29 separate locations.

The attack, involving 704 total aerial weapons, was Russia’s largest overnight bombardment since Oct. 29, when it launched 705 munitions, according to Ukrainian air force data reviewed by ABC News.

The biggest single-night assault of the war remains the strike on Sept. 6, which involved 823 air attack vehicles. The latest barrage marks only the fourth time during Russia’s full-scale invasion that Moscow has deployed more than 700 airborne weapons in a single night.